If I do nothing for a second or two, the screen goes black and then my screen starts searching for signal on the digital, analog, digital etc ports implying there is no signal.
This is intermittent for me in that when I'm happily computing without problems for an hour, this sometimes suddenly occurs, every other week maybe.

Comment #22 from the above bug report works for me so that I don't have to restart X or reboot, but the problem will reoccur somewhere in the future.